High carbon pitch compositions



Feb. 9, 1932. s. P. MILLER 1,844,900

HIGH CARBON FITCH COMPOSITIONS Filed Dec. 29. 1927 3 Sheets-Sheet l Feb.9, 1932. s. P, MILLER 138445900 umu CARBON P11-ca couros'lnons. y

Fild Dec. 129. `1927 K s sneets-sneet 2 E ge f:

- i INVENTOR BY @awww-Jl WMI/Lam. ATTORNEYS Feb. 9, 1932. s. P. MILLERHIGH CARBON FITCH COMPOSITIONS Filed Deo. 29. 1927 3 Sheetsheet 3INVENTOR @f6/Ww@ Wd/L Y gama/j AT TORNEYS Patented Feb. 9.,

UNITED STATES PATENT orrlcs STUART PBMELEE' MIILI'JIIEB.,v OF'ENGLEWOOD,NEW JERSEY, SSIGNB T0 THE `IBARREl". COMPANY, OF NEW YORK, N. Y., ACORPORATION OF NEW JERSEY HIGH CARBON' FITCH COHPOSITIONS Applicationmed December 29, 1927. Serial No. 243,808.

This invention relates to new pitch com.

positions. The invention relates Aparticularly to pitch compositions ofregulated high .carbon content.

In the ordinary operation of by-product coke oven and gas retort plants,the coal distillation gases are cooled to separate tar therefrom andthetar is shipped to tar distillation plants for distillation. The pitches1o produced from ordinary coke oven tar have too low a free carboncontent to make them available for certain purposes. Pitches containinga high free carbon content are obtained ordinarily from the distillationof l5 gas retort tars, articularly horizontal gas retort tars, or t eadmixture of such tars with coke oven tar and the distillation of themixture. So also, pitches produced from gas retort tars alone may nothave the proper 2o carbon content and other properties.

According to the present invention, thel the tar and p1tch, I use theseterms in their ordinary meaning to include not only elemental ormolecular carbon but also'those constituents which remain as insolubleresidue on digestion of the tar or pitch with benzol or similar solvent.It may include certain inorganic impurities as well as insolublehydrocarbons of high molecular weight.

In my companion application, Serial No 243,307 I have described theproduction of new high carbon pitches at coke oven or collecting thegases from near the end'of the coltingperiod,coolin the gases toseparate high carbon tar there om, and distilling the high carbon tar toproduce new hi h carbon 5@ lpitches. The present invention pr uces newother coal distillation plants byseparately' products of a composite andsomewhat different character. The new high carbon pitches produced inaccordance with said companion application can advantageously beemployed according to the present invention in producing the newcomposite pitchl products.

In my companion application, Serial No. 243,305 I have described theproduction of low carbon pitches by separately collecting the gases fromthe early period of the coking operation, cooling the gases to separatea low carbon tar therefrom, and distilling such tar to .produce lowcarbon pitches; and in my companion application, Serial No. 243,306. Ihave described the blending of such pitches with tar to give newcompositepitch products. The productionof theV new products 0i. suchapplications,y can if desired, be combined with the production of theproducts of the present invention; although the present invention is notlimited to operations which it is so combined with the processes and theproduction of the companion applications.

In the practice of the present invention, I provide for the separatecollecting of the products of such coke oven or other coal distillationgases given olf during the later portion of the coking operation, whenthe gases are lower in tar content, and when the tar content ofthe gasesis a higher carbon tar than during the earlier period of the cokingoperation. These gases with their high carbon content are cooled toseparatetherefrom a high carbon tar, which tar is subjected todistillation orthe production therefrom of a high carbon pitch. Theseoperations can be carried out in accordance with the process and toproduce the product described in m companion'application, Serial No.243,30; but the distillation of the tar will be carried to such a pointthat a relatively high melting point pitch will be produced of highcarbon content, 'which pitch then blend with additional tar or lowermelting point pitch to produce new composite products.

The present invention is of articular value for the production of highcar on pitch prodv ucts of relatively low melting point and of highercarbon content than can be obtained by the ordinary distillation of coaltar. For example, for certain purposes such as roadmaking purposes,relatively low melting point pitches are required having a melting pointaround 105 to 110 F. and containing a carbon content around 12 to 15%.Such pitches ordinarily require the addition of high carbon gas retorttar to coke oven tar before distillation. Such pitches can readily beproduced according to the present invention by subjecting the highcarbon tar from the coke oven gases to distillation to produce a highcarbon pitch of high melting point and then blending this pitch inproper proportion with tar or soft pitch, either Without or with furtherdistillation of the mixture to remove additional oils therefrom. Forexample, the high carbon pitches can be produced of melting point around145 to 165 F., or even around 225 or 250 or even 300 F., or higher, andsuch high carbon pitches can then be blended with tar or sot pitch toproduce the new composite products.

The distillation of the high carbon tar and the production of the highcarbon pitch which is to be blended with the additional tar or softpitch is advantageously carried out at the coke oven or gas retort plantby bringing the tar into direct and intimate contact with the hot coaldistillation gases; and this operation can be carried out in acontinuous manner, with the continuous production of the high carbonpitch, and the continuous blending of such pitch with the tar or soitpitch to pro uce the new composite products in a continuous manner.

In the production of the' new product at coal distillation plants, forexample, at coke oven plants, I provide a plurality of collector mains,one for the gases from near the end of the coking operation from whichthe high carbon tar is to be separated, and another for the gases fromthe earlier period of the cok-k ing operation from which a lower carbontar is separated; and I provide in addition separate condensing systemsfor the further condensation of light tar or tarry oil from therespective gases. The heavy tars from the collector mains and thelighter tars or ytarry oils from the condensers are kept separate. Thehigh carbon tars from the collector main and condensers may be combinedtogether for distillation yor distilled separately. Similarly, the lowercarbon tars from the collector main and condensers may, if desired, besubjected to distillation either in admixture or separately to producelow carbonpitches, although such low carbon tars can be utilized forother purposes.

In addition to such separate condensing and collecting systems andapparatus for keeping separate the respective tars, I provide adistillation apparatus for distilling the high carbon tar or tarstogether or separately, which distillation apparatus is advantageouslyone in which the distillation is eifected by direct and intimate contactwith hot coal distillation gases. This can be carried out in variousways, such as by the provision of a still or short collector main intowhich the tar to. be distilled is introduced and into which the gasesfrom a selected number of ovens are introduced at a high temperature,and in which the tar is brought into intimate contact with the hotgases, as by spraying or atomizing the tar into the gases by means ofspray nozzles or mechanical agitating devices such as rotary discs orrotary rolls, etc., rotating at a high rate of speed to atomize the tarand bring it into intimate contact with all parts of the gas in thestill. By introducing the high carbon tar continuously and withdrawingthe high carbon pitch' continuously, the high carbon pitch is availablein a highly heated state for lblending with the tar or soi't pitch andthis blending can advantageously be carried out with utilization oi theheat of the hot pitch for assisting in the blending operations and forheating and in some cases if desired, for distilling the lighter oilsfrom the tar blended therewith.

The character and particularly the melting point of the pitch producedmay be varied by varying the extent to which the distillation iscarried, but the distillation will in most cases be carried suiiicientlyto produce a pitch of relatively high melting point, as compared withthe melting point of the desired pitch composition. The maximum meltingpoint will in some cases be limited by the free carbon content of thepitch, since a veryhigh carbon content pitch is in general moredifficult to handle and to circulate and to keep iiuid than a pitch oflower free carbon content but of corresponding melting point. Ingeneral, however, the melting point of the high can bon pitch producedwill be determined by the desired character of the pitch compositionresulting from the blending of the high carbon pitch with tar or with alower melting point pitch. For example, a pitch of a melting point ofabout 105 to 110 F., to be used for road construction can be made byblending pitch of not higher than 165 F. melting point with the requiredamount of tar to reduce the melting point to 105 to 110 F. However, itis readily possible to produce high carbon pitches of melting points upto 300 F. and in some cases up to 400 F. or higher. Such distillationgives a high yield of oils of high specific gravity and some of them ofhigh boiling point. Some increase in carbon content may take placeduring the distillation of the high carbon tar by means of the hot cokeoven gases, but this increase will be much less than when the highcarbon tars are distilled in ordinary externally heated tar stills. Thecarbon content ol' the pitch can be regulated and controlled to agreater tion of the coke ovens during which the gases of 3o thecollector main in W are collected for the separation of tar therefrom,therebyrecovering tars of higher or less high carbon content, from whichpitches of somewhat varying high carbon content can be produced.

rlhe tar which is blended with the high carbon pitch, acconding to thepresent invention, may be varicdin accordance with the character of thecomposite pitch desired. For some purposes, the tar to be blended withthe high carbon pitch may itself be high carbon tar such as is separatedfrom the leangase's near the end of the coking operation. Blends of suchtars With the high melting point and high carbon pitches will givecompositepitch products of intermediate melting point but of relatively'high carbon content. For some purposes, a much lower carbon content ofthe blended mixture is suthcient, and, in such cases, the tar blendedwith the high carbon pitch maybe ordinary coke oven tar with its normalcarbon content, that is, colte oven tar such as is obtained when thetotal tar from the various ovens is collected together. ln somecases,the low carbon tars produced from the rich gases given oil during theearly period the colring operation nia-y be blended to a greater or lessextent to regulate and control the carbon content of the blendedproduct.

The separate collection of high and low carbon tars at the coke ovenplant and the separate distillation of the high carbon tar to producehigh carbon pitch gives 1arious products at the colte oven plant forblending in an undistilled condition with the high carbon pitch.' F orexample, theheavy tar from hich the high carbon tar is collected, may beemployed for blending purposes, and its relatively lower oil contentmakes it particularly' valuable for that purpose. So'V also, Whereordinary heavy tar from the collector main in which all of the tar fromthe ovens is collected together, is available, this may be blended with'the high carbon pitch to form new composite products. The tar which isblended with the 'high carbon pitch may itself be subjected yto aninitial or partial distillation to dehyrate it or to free it from lowerboiling oils, although inl some cases the raw tar may be employedwithout such distillation or dehyration. `By reguvlatiirigthe lamount ofthe'tar and pitch blended with each other and the carbon content of thepitch and the tar, composite products of intermediate carbon contentand` point can be produced, and this canbe regulated by regulating andcontrolling the character of the individual products'which are blendedwith each other. I do not, however, exclude the blending of tars otherthan coke oven tars with the new high carbon pitches,

since in some cases tar from other sources, may be employed.

-melting The products of the blending'of diierent tars,` etc., with thehigh melting point high carbon pitches,

pitch with tar is accomplished preferably by introducing continuousstreams; of the hot thinly iluid materials to be blended into a suitablereceptacle, the streams being directed so that they vflow together andthus immediately produce `a uniform blended product. Such operation isparticularly desirable if the tar which is introduced contains Waterbecause the temperature of the pitch may be such as to vaporize theWater immediately together With some of 4the more volatile constituentsof the tar,r thus producing a dehydrated product. The vaporizedwater andoil constituents can be withdrawn continuously from the receptacle andthe oil can be condensed by the provision of a suitable condenser. Theoil can, after separation of Water, be returned to the pitch, ifdesired. rlhe blended product can likewise be Withdrawn continuouslyfrom the receptacle and deliyered to suitable storage containers.

As an example of the practice of the invention the gases from the latterportion of the colring period oi a coke oven plant can be cooled in theseparate collector main by ammonia liquor or ammonia liquor and tar4supplied thereto and the separated heavy tar containing a relativelyhigh free carbon Lcontent can be distilled then in a separatedistillation main by contact with the hot gases from the ovens toproduce a pitch having' a melting point ci, for example, from 165 to2259 F. or up to 300 F. or higher. To produce a. road-treating' pitchhaving a melting pointof 'approximately 105 l?, and a free carboncontent of around l2 to 15%, the desired high melting point pitch can beblended continuously in the manner described with av suitable proportionof raur tar from the saine plant from other cokeV oven batteries or',with tar from gas retorts or similar coal will differ incharacteristics, depending upon the nature of the materials' icoy amountcan be determined readily by test 'and the blending can be so conductedas to produce a uniform road-treating pitch having the desired meltingpoint with the proper proportion of free carbon.

In applying the invention at gas retort plants, or With gas retort tars,it is possible to produce new composite pitch products varying with theparticular tar employed. Horizontal and inclined gas retort plants,Which give high carbon tars, will give unusually high carbon tars fromthe gases given oil during the latter part of the gas making operation,and these tars on distillation will ican he blended, "rind to give aproducts, or re lower carbon carbon tars ration of interdistillation#tent than tr produced lower than, pints, or

give high carbon. pitches v" with additional tar oi' unusually highcarbon with lower carbon tai i pitch compositions. m from the later parto mittent vertical r give pitches oi' those obtained fr at such plants,but i that obtained at horl.J even at eolie oven plant various highcarbon ,A itches y ing kinds a Wide i composite blended products can bepreduceda The invention may a coke oven plants or to re out anyconsiderable ino except for the provision ot lector mains7 separate cccles and the dist rat-us. The op the recovery oi v... not been availableheretoio s L ants,ivitli i vthereof re as the result or Coke oven or gasretort operation.

The production oi the new compositions will be further des""bed inconnection with the accompanying dran/'ings ii ivhich- Fig. l is a planviert ot a portion ot a colic oven battery;

Fig. 2 is a cross-sectional vier? oli one of the collector mains;

Figs. 5 and a are enlarged sectional views of the short collector mani;n l

Figs. 5y and G are details n section of the blending apparatus.

Referring to the drawings, 5 indicates a battery oi' ovens Which areconnected by uptake pipes and goose-necks G to rali/e boxes 7 whichcommunicate with collector mains 8 and 9. Valves 10 are arranged thevalve boxes to permit the direction of the hot coke oven gases into oneor the other of the collector mains, depending upon the stage of thecoal distillation operation in the particular oven to which the valvebox is connected. Thus. by operating the Valves rich and lean gases fromthe several ovens ot the battery can be collected separately in thecollector mains wherein they are cooled to the desired extent by ammonialiquor introduced through spray nozzles ll which are supplied through apump 12 and pipe 13 from. a source of ammonia liquor such as a tank 15.'

From the collector mains the gases carrying oil vapors and partiallycondensed tarry constituents are delivered through cross-over mains 16and 17` to condensers 18 and 19 in which the gases are further cooledtoseparate the tarry oil constituents1 The oil, together with ammonialiquor, can be Withdrawn through pipes 20 and 2l and delivered todecanters 22 and 23 wherein. the ammonia liquor is -separated Jfrom 'thetarry oil. The tarrv oil can be delivered to suitable storagereceptacles and the ammonia liquor can be returned if desired forfurther use as a cooling medium either in the collector mains or in thecondensers. The gases escaping from the condensers are delivered throughpipes 2li and 25 to exhausters 26 and 26 and thence to equipment (notshown) for the separation of ammonia, light oils, etc.

The tar which separates in the collector mains can be Withdrawn throughpipes 27 and 28 to decanters 29 and 30, in Which ammonia liquor isseparated While the tar is stored in tanks. rlhe ammonia liquor may bereturned to the collector mains for cooling or may be utilized torecover ammonia therefrom. rl`he tar from the lean gas main contains arelatively high. proportion of free carbon and this tar is subjected todistillation in a suitable still such, for example, as a short collectormain or still 31 which is dis-- posed preferably at the' rear of theovens and is connected to a plurality of ovens so that het coaldistillation gases pass continuously through the short collector main orstill. The tar to be distilled may be introduced to the short collectormain or still at one end through pipe 32 by pump 33. The collector mainor still 3l is filled with a cylinder 84 adapted to be rotated at a highrate of speed. by electric motor 35. The cylinder dips into the body oftar and pitch inthe bottom oi collector main or still 31 and atoinizesthe tar andpitch, in the` form ot a finely disseminated sp1-ay, into thegases passing through the collector main or Astill 3l. The are thuseffectively scrubbed by the tar and pitch. In thus mingling with the hotgases the tar is distilled to produce pitch'ivnich is Withdrawncontinuously at 36 and the volatile constituents are separated and jointhe gases which run through settling tower 1G in which the tar spray andglobules and other entrained matter settle out of the scrubbed gases andare returned to the collector main or still 8l. The tower 46 may ifdesired contain baffles or packing. The gases may be Withdrawncontinuously through a pipe 37 and delivered to a condenser 38 locatedat any suitable place, Wheein the oil constituents can be separated fromthe gases. Thereafterl the gases may be delivered through a pipe 39 toan exhauster and mingled with the remaining gases from the ovens of thebattery.

The pitch produced is withdrawn continuously at 36 into receiver 47 fromwhich it is conveyed by pipe 40 and delivered to the blending apparatusll comprising a chamber into which. the pitch, still at hightemperature, is introduced. The tar or other material to be blended withthe pitch is similarly introduced through a pipe 42, the two pipes beingdirected so that the streams are mingled as they enter the chamber asshown in Fig. 6. The tar and pitch thus intimately mingle and blend toproduce a product having the delighter oil constituents will bevaporized immediately upon contact between the tar and pitch. The vaporcan be withdrawn as it is released vthrough a pipe 44 and delivered to Ya condenser 45 wherein it is cooled. The oil thus recovered can beImixed with oil obtained by the cooling of other gases from the system,or can be returned to the pitch in I The mixing of the hot high carbonpitch,

while at a high temperature, with the tar in the mixing chamber 4l,preferably takes place continuously, and any ioaming'due to heating ofcoal ta'r containing water by the hot pitch is readily taken care of.The continuous ow of the tar and the pitch causes the blending of thepitch and tar continuously to give a resulting composite blended productwhich is still suiiiciently hot to be thinly fluid and to run from theapparatus, although the blended product on cooling may be e Vsolidproduct oi higher or lower melting point. VThe tar which is thus addedto and blended with the hot high carbon pitch may itself be preheatedand dehydrated or partly distilled to remove part vof the light oilstherefrom, although such preheating and 4dehydrationmay in some cases beomitted and raw wet tar employed. The tar may, as above pointed out, beitself a high carbon tar,

or a low carbon tar, or an ordinary normal carbon tar, depending uponthe carbon content and other properties Voie the blended product. rlhetar need not he a coke oven vertical retort tar, low temperature tar,etc.

rl"his production of the new blended product is carried out at a cokeoven plant, with elimination ot' the transportation of coke oven tar totar distillation plants or of high carbon gas retort tar to tardistillation plants, and with the production of the new compositeproduct-by distilling only a limited amount of high carbon tar which,however,

.is distilled to give a large yield .of oils therefrom of high specificgravity ,andf relatively high boiling point; A

The new composite pitch products will be l ,made up of the tar utilizedin producing them and of the high carbon pitch blended therewith to forma homogeneous product.

These composite l productswill diiier in char-V acter from pitches ofthe same melting point produced by direct distillation of the highcarbon tar.

The process of producing the newfcompof site products diiers from theprocess of proi ducing the new high carbon pitches of my companionapplication, Serial No. 243,307, in that it does not rely upondistillation of all of the tar employed to produce the pitch desired,but subjects only part of the high tional undistilled tar to produce thenew composite products. The production of' the 'new compositions`involves the distillation of less tar, but distillation to 'a muchhigher melting point pitch, as compared with the productionof thecompositions of said companion application when such pitches are ofintermediate melting point.

In its broader aspects, production of the new compositions is notlimited to the continuous distillation of the tar to produce the highcarbon pitch, nor is it limited to the continuous blending of the hothigh carbon pitch as produced with the tar, although the process isadvantageously carriedl out in a continuous manner with continuousdistillation ofthe .tar and continuous production of pitch and withcontinuous blending of the hot high carbon pitch with the raw tar, orwith specially treated tar, to produce the new composite pitch products.

While production of the new pitch cornpositions has been moreparticularly described in connection with coke oven operation and theproduction of coke oven tar pitches, it is applicable to other coaldistillation plants and ters, such as certain gas retort plants andters, to produce new conposite pitch products.

l cleirn l. New composite blended pitch composi- A Y tions, comprisinghigh free carbon pitch of tar, hut may he water gas tar, gas house tar,

high melting point blended with a substantial amount of coal tar, saidcoal tar including low boilingI constituents not present in a straightdistillation pitch of the same melting point as the composite blendedpitch composition, the high carbon pitch .resulting from thedistillation of high carbon tar produced from colte oven orother coaldistillation `gases during the latter period of the Coking of coal incolte ovens or other distillationy of high carbon colte oven tarrecovered fromcoke oven gases during the latter period of thecolring ofcharges of'coal in coke ovens, the coke oven tar compr1s1ng lowerboiling constituents not present in a pitch produced by the strei htdistillation of th'e coke oven tar to pito of the same melting point asthe composite blenced pitch 5 composition.

In testimony whereof I ax my signature.

STUART PARMELEE MILLER.

